This application addresses broad Challenge Area (06) Enabling Technologies and specific Challenge Topic, 06-DK-103: Enabling Technologies in Imaging. Determination between benign and malignant strictures in the bile ducts is difficult. Although non-invasive imaging modalities can locate the stricture, a definitive diagnosis cannot be made without an optical measurement of cells and tissue as no biomarker exists. Peroral cholangioscopy is the least invasive method to optically image the bile ducts but to reach a stricture requires a long, flexible, and small-diameter endoscope. The current technology of an imaging sensor or optical fiber for each pixel in the acquired image does not allow both ultrathin and high-resolution endoscopy, making the clinician legally blind when imaging the bile duct. A new technology is proposed that puts a small microscanner at the tip of a catheter, making a rigid tip of only 9-mm and a rugged flexible shaft with a 6-mm bending radius. Previously this catheterscope with distal-tip microscanner can acquire 600-line color images at 30 Hz (video rate) and bile duct imaging has been performed in a live pig. In this proposal, the addition of tip bending and a doubling of the optical resolution to HDTV (1024 lines) will be developed for a new steerable "guidewire with eyes". The proposed new guidewire with eyes will be 1.2 to 1.6 mm in diameter, approximately twice the diameter of a standard guidewire. New cannula-style brush and forceps tools will be developed for image-guided biopsy and tested first in pig bile ducts and then in at least 20 human subjects, split between having benign and malignant causes of the stricture. Since the 1-mm catheterscope may be able to traverse the stricture, staging or lateral extent of any suspected carcinoma will be measured. Additional clinical advantages of this scanning catheterscope are that the low-power, red, green, and blue laser light is inherently narrow band and both enhanced spectral imaging and zoom magnification are user-controlled real-time features. By enhancing image contrast and feature size, biopsy site selection can be improved and no longer does the clinician have to be legally blind during an endoscopic retrograde cholangiography procedure. In the future, when bile duct surveillance is more common, the laser illumination can be changed to measure fluorescence biomarker signatures of early cancer and pre-cancer without adding size, cost, or complexity to the probe. PUBLIC HEALTH RELEVANCE: Determining diagnosis and extent of disease in the bile duct is extremely difficult, and with current endoscope technology these decisions are being made with clinicians legally blind. Therefore, a new laser scanning technology for image-guided diagnosis of disease in the bile duct is proposed that affords high quality video imaging. This new technology will be developed and tested for the purpose of improving the efficiency and accuracy of diagnosing bile duct diseases, especially cancer from benign complications that can mimic this deadly disease. The goal of this project is to provide biopsies with higher accuracy and diagnostic yields, while introducing a less invasive clinical instrument. Having a more effective and less invasive clinical instrument is expected to lower overall cost for managing patients with indeterminate biliary strictures.